title: Biochemical properties of poplar thioredoxin z.
abstract: Trx-z is a chloroplastic thioredoxin, exhibiting a usual WCGPC active site, but whose biochemical properties are unknown. We demonstrate here that Trx-z supports the activity of several plastidial antioxidant enzymes, such as thiol-peroxidases and methionine sulfoxide reductases, using electrons provided by ferredoxin-thioredoxin reductase. Its disulfide reductase activity requires the presence of both active site cysteines forming a catalytic disulfide bridge with a midpoint redox potential of -251 mV at pH7. These in vitro biochemical data suggest that, besides its decisive role in the regulation of plastidial transcription, Trx-z might also be involved in stress response.
authors.affiliation: UMR 1136 INRA Nancy University, Interactions Arbres-Microorganismes, IFR 110 EFABA, Faculté des Sciences, 54506 Vandœuvre-lès-Nancy, France.
authors.forename: Kamel
authors.initials: K
authors.lastname: Chibani
authors.forename: Lionel
authors.initials: L
authors.lastname: Tarrago
authors.forename: Peter
authors.initials: P
authors.lastname: Schürmann
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Jacquot
authors.forename: Nicolas
authors.initials: N
authors.lastname: Rouhier
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D004579:Electron Transport; D007506:Iron-Sulfur Proteins / Q000378:metabolism; D010088:Oxidoreductases / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism*; D018087:Plastids / Q000378:metabolism; D032107:Populus / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D013880:Thioredoxin-Disulfide Reductase / Q000378:metabolism; D013879:Thioredoxins / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D007506:Iron-Sulfur Proteins; D010940:Plant Proteins; D013879:Thioredoxins; D010088:Oxidoreductases; C021588:ferredoxin-thioredoxin reductase; D013880:Thioredoxin-Disulfide Reductase